Specified cast is not valid error thrown at login

After upgrading to 7.5 from 7.0 we receive a "Specified cast is not valid" error at login.

Any clues appreciated.

Dear Steve,

Please open a Support Request for this and include the following information:

- Has there ever been a conversion from a MySQL to MSSQL database?
- In database 'dwsystem', table 'DWUser', what data type has the column 'active'?

Best regards,

Thomas Esser
Senior Specialist Software Support Team RED EMEA